Two-part gas-collecting hood for converter

ABSTRACT

A gas-collecting hood for a steel-making converter has a fixed upper ring formed by an array of heat-exchanger tubes and a similarly formed lower ring which surrounds and telescopes with the upper ring and may be dropped down around the mouth of the converter. A chain seal is provided which rests on a ledge formed by an outwardly bent flange at the top of the lower ring and which engages the exterior of the inner ring. This chain is formed of a plurality of rigid links which are fitted and pivoted together by means of integrally formed pins and holes as in a sprocket chain.

United States Patent [191 Hegemann et al.

[111 3,799,520 [451 Mar. 26, 1974 TWO-PART GAS-COLLECTING HOOD FOR CONVERTER Primary Examiner-Gerald A. Dost [75] Inventors: KarLRudolf Hegemann, Essen; Attorney, Agent, or Firm-Karl F. Ross; Herbert Giinther Finger, Wesel; Munir D b Pasambegovic, Essen, all of u no Germany [73] Assignee: Gottfried Bischoff Bau kompl.

Gosreinigungs-und [5 7] ABSTRACT Wasserruckkuhlanlagen Kommandirgesenschaft Essen, A gas-collecting hood for a steel-making converter has Germany a fixed upper rmg formed by an array of heatexchanger tubes and a similarly formed lower rmg [22] F'led: l 161 1973 which surrounds and telescopes with the upper ring 2 APPL 351 9 and may be dropped down around the mouth of the converter. A chain seal is provided which rests on a ledge formed by an outwardly bent flange at the top of [52] US. Cl. 266/19 the lower ring and which engages the exterior of the [5 1] Int. Cl. C2lc 5/38 inner i This Chain is f a plurality f rigid [58] held of Search 266/35 36 links which are fitted and pivoted together by means 266/19 of integrally formed pins and holes as in a sprocket chain. [56] References Cited UNITED STATES PATENTS 9 Claims, 4 Drawing Figures 3,396,958 8/1968 Maehara et a1 r. 266/35 PATENTEU MR2 6 I974 SHEET 3 OF 3 FMGIJ TWO-PART GAS-COLLECTING HOOD FOR CONVERTER FIELD OF THE INVENTION This invention relates to a hood for use with a steelmaking converter or the like. More particularly this invention concerns a hood comprised of a pair of rings, one fixed and one displaceable, used for carrying away the gases generated in a steel-making converter.

BACKGROUND OF THE INVENTION The gases generated in steel production in a Bessemer or other converter are often toxic and issue from the mouth of this converter at high temperatures, entraining dust and corrosive or agressive compounds. These gases cannot simply be released in the mill so that a gas-collection hood of some type is usually arranged above the converters mouth. Due to the temperature of these gases it has been found necessary to cool the walls of the hoods, e.g., by passing steam or another coolant through tubes forming or welded to its walls. The cooling may be effected by evaporation of water in the tubes. I

In order to keep leakage at a minimum the hood is usually formed in two parts, i.e., a fixed upper ring and a displaceable lower ring which telescopes in or around the upper ring. The bottom of the lower ring is dropped down onto the converter mouth during operation thereof. A gap is left, however, between the lower ring and the upper ring which allows some shifting of these two elements relative to each other, which shifting is unavoidable in such a high-temperature process- In some arrangements a ring-type seal is provided between the two telescoping elements and has an outer periphery bearing against the inside of the outer ring and an inner periphery bearing against the outside of the inner ring.

Another arrangement uses a water seal, with the base of the upper ring vertically displaceable in a body of water held in a collar on the lower ring. Such a system, wherein metal parts are exposed to water vapor at high temperature, acid constituents of the gas, etc., leads to quick disintegration of the seal elements and is relatively expensive to maintain.

Yet another arrangement includes labyrinth-free seals into which a gas-outflow blocking fluid is forced. Such an arrangement uses up a great deal of energy and the nozzle openings are often obstructed by solid particles carried in the gases coming out of the converter.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide an improved hood arrangement for a steelmaking converter or the like whereby the aforementioned disadvantages are avoided.

Yet another object is the provision of a low-wear, economical and efficient hood which forms a tight seal with the mouth of the converter.

A further object is to provide a hood wherein displacement of one of the ring elements laterally relative to the other is possible without significant gas leakage into or out of the system.

SUMMARY OF THE INVENTION These objects are attained according to the present invention in an arrangement wherein the lower vertically displaceable ring is formed with an outwardly bent upper ledge or flange on which a sealing ring rests. This seal is a chain of rigid elements so that the seal is flexible in a plane perpendicular to the axis of the system but mechanically nonextensiblle. The inner periphery of the chain engages against the outside of the upper fixed hood ring while the bottom surface simply rests on the ledge of the lower ring. In this fashion, displacement of the lower ring relative to the upper one or deformations (e.g., thermal) of either ring are compensated for by the seal which readily adjusts to such displacement or deformations.

According to another feature of this invention both rings are formed as basically cylindrical or frustoconical arrays of vertical parallel tubes through which a heat-exchange medium such as steam is passed. The outside of the inner ring and the ledge of the lower ring is provided with a reinforcing plate: or apron to prevent any excessive wear by the movement of the heavy chain which rests by its weight on the flange.

In accordance with further features of this invention the chain is formed of metal (e.g., cast iron), of heavy ceramic, or of hematite links which are pivoted together by short pins engaged in recesses in the links. The chain is tightened about the inner hood ring by replacing a link with another having a smaller spacing between pivots. Thus in fabrication the chain is formed largely of standard-size links and the last link or links are of the particular size needed to make a snug fit. The links are flat and lie on one another so as to form a sort of labyrinth seal that thoroughly prevents leakage from inside the hood. According to a feature of the invention each link comprises a pair of flat lugs or tongues at its ends overlapping with the similar lugs or tongues of the adjacent links, and a block portion having twice the thickness of the tongues integral and unitary with the lugs or tongues. The ends of the lugs or tongues with rounded surfaces having radii of curvature centered on the pin or stud axes and slidingly engaging and spaced with slight tolerances from concave surfaces of the block portion of the link to which the tongues are pivoted. The links are alternately turned upwardly and downwardly and bear a stud on one tongue and a bore receiving the stud of an adjoining link on the other tongue.

DESCRIPTION OF THE DRAWING The above and other objects, features, and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a vertical section through the arrangement according to the present invention;

FIG. 2 is the detail of FIG. 1 indicated by arrow II, in enlarged scale;

FIG. 3 is a top view of the detail shown in FIG. 2; and

FIG. 4 is a perspective view of one of the links of the chain of FIG. 3.

SPECIFIC DESCRIPTION A Bessemer converter 3 has an upwardly open mouth 14 with a flat planar rim 15. A hood! has an upper fixed portion 1 which leads to the filters and similar devices, preliminary to a chimney or stack, which remove the impurities from the gases escaping from the converter 3 and a lower vertically displaceable portion 4 which is engageable with the rim 15.

The upper ring 1 is formed of an array of tubes 1 1 extending between circular manifolds 16 and 17 carried on a support 18. The inner surface 19 of the upper ring 1 is basically frustoconical and upwardly tapered while its outer surface 12 is cylindrical.

The lower ring 4 is vertically displaceable by a drive 2 including hydraulic cylinders 20 connected via a link 21 to a support plate 22 carrying an upper manifold 23 and connected via another link 24 to a lower manifold 25. Tubes 11 extend between these manifolds and form an upwardly converging frustoconical inner surface and a horizontal flange or ledge 5. The links 21 and 24 which lie in a horizontal plane allow the array 4' of tubes 11' to move on the rim 15 relative to the center axis A of the hood.

As shown in FIGS. 2 and 3 there is provided atop the ledge a chain 7 formed of identical links 6 formed of hematite-like kiln furniture by sintering a shaped mass formed of a mixture of crushed hematite, a binder and water. Each of these links, as shown in FIG. 4, has tow outwardly convex ends 26 and a central upstanding region 27 having two outwardly concave sides 28 each adapted to fit with slight play against a corresponding end 26 of another link 6. To one side of the ridge 27 the link is provided with an upstanding pin 9 and to the other side with a similar cylindrical hole 10. The pin 9 of one link is received with slight play in the hole of the neighboring link so as to pivot them together like a sprocket chain.

The chain 7 has an inner periphery 8 which fits snugly against the surface 12 of the upper hood half 1. This surface 12 is formed by metal strips 29 welded between and projecting from the vertical tubes 11. In addition the top of the lower tube array 4 is reinforced by an annular flat metal plate 13 welded to the ledge 5 so as to prevent the ceramic links 6 from wearing out these tubes 11'.

The overall length of the inner periphery 8 is made to correspond as exactly as possible to the circumference of the outer surface 12 of the upper half 1 by the use of links which are provided with different overall lengths L. Thus when the links 6 wear at their inner periphery and the chain 7 loosens, one of the links is removed and replaced with one of slightly shorter length L.

We claim:

1. A gas-collecting hood for a converter, comprising:

a fixed upper ring connected to an outlet and spacedly juxtaposed with a mouth of the converter; a vertically displaceable lower ring surrounding said upper ring and having an upper side forming an outwardly extending annular support ledge and a lower side engageable with said converter around said mouth; and

a chain collar resting on said ledge and radially inwardly engaging said upper ring, said collar being formed of a plurality of interconnected rigid links.

2. The hood defined in claim 1 wherein at least some of said links are provided with an upstanding pin and at least others are formed with a hole, the pins of said some of said links engaging in the holes of the other links.

3. The hood defined in claim 2 wherein each of said links is formed with curved ends fitting against correspondinglycurved ends of the other links.

4. The hood defined in claim 1 wherein said links are formed of hematite.

5. The hood defined in claim 1 wherein each of said links is elongated and has outwardly convex ends and is formed with a central upstanding region having ends of a concavity corresponding to the convexity of the first-mentioned ends, the first ends of each link fitting with the second-mentioned ends of the adjoining links in said chain.

6. The hood defined in claim 5 wherein each link is formed to one side of said upstanding region with an upstanding cylindrical pin and to the other side of said upstanding region with a hole, the pin of each link fitting in said chain into the hole of the neighboring link.

7. The hood defined in claim 1 wherein said upper ring is constituted by an array of coolant tubes and at least one metal wear-resistant apron, said chain having an inner periphery engaging said apron.

8. The hood defined in claim 1 wherein said lower ring is constituted by an array of heat-exchange tubes and an annular plate attached thereto and forming said ledge.

9. The hood defined in claim 6 wherein said links each comprise a pair of tongues lying in a common plane and unitarily formed with an extending in opposite directions from the respective upstanding region, one of said tongues of each link being formed with a respective such pin, the other tongue of each link being formed with a respective such hole, the ends of said tongues having radii of curvature centered on the axes of said pins and said holes, the upstanding regions having a thickness equal to twice that of the respective tongues, alternate links of said chain having opposite orientations. 

1. A gas-collecting hood for a converter, comprising: a fixed upper ring connected to an outlet and spacedly juxtaposed with a mouth of the converter; a vertically displaceable lower ring surrounding said upper ring and having an upper side forming an outwardly extending annular support ledge and a lower side engageable with said converter around said mouth; and a chain collar resting on said ledge and radially inwardly engaging said upper ring, said collar being formed of a plurality of interconnected rigid links.
 2. The hood defined in claim 1 wherein at least some of said links are provided with an upstanding pin and at least others are formed with a hole, the pins of said some of said links engaging in the holes of the other links.
 3. The hood defined in claim 2 wherein each of said links is formed with curved ends fitting against correspondingly curved ends of the other links.
 4. The hood defined in claim 1 wherein said links are formed of hematite.
 5. The hood defined in claim 1 wherein each of said links is elongated and has outwardly convex ends and is formed with a central upstanding region having ends of a concavity corresponding to the convexity of the first-mentioned ends, the first ends of each link fitting with the second-mentioned ends of the adjoining links in said chain.
 6. The hood defined in claim 5 wherein each link is formed to one side of said upstanding region with an upstanding cylindrical pin and to the other side of said upstanding region with a hole, the pin of each link fitting in said chain into the hole of the neighboring link.
 7. The hood defined in claim 1 wherein said upper ring is constituted by an array of coolant tubes and at least one metal wear-resistant apron, said chain having an inner periphery engaging said apron.
 8. The hood defined in claim 1 wherein said lower ring is constituted by an array of heat-exchange tubes and an annular plate attached thereto and forming said ledge.
 9. The hood defined in claim 6 wherein said links each comprise a pair of tongues lying in a common plane and unitarily formed with an extending in opposite directions from the respective upstanding region, one of said tongues of each link being formed with a respective such pin, the other tongue of each link being formed with a respective such hole, the ends of said tongues having radii of curvature centered on the axes of said pins and said holes, the upstanding regions having a thickness equal to twice that of the respective tongues, alternate links of said chain having opposite orientations. 